研究了2.45GHz微波场中I型乙烷水合物及II型丙烷水合物的热激分解过程,基于晶体表面两步分解机制的动力学模型,结合传热传质分析了其分解特性.结果表明:水合物在微波场中的加热分解是一个与实际微波电磁场相互耦合的过程,微波体积加热的特点强化了水合物颗粒表层的传热传质过程,时间累积的热效应增大了水合物晶体破解速率;在120至540W入射功率下,乙烷、丙烷水合物气化速率分别达到0.109-0.400mol·min-·1L-1及0.090-0.222mol·min-1·L-1.在一定范围内增大微波功率可显著提高水合物分解速率,其中乙烷水合物一直处于功率主控区,丙烷水合物更早进入功率和分解动力机制共同控制区.
The decomposition of type I ethane hydrate and type II propane hydrate stimulated by 2.45 GHz microwave(MW) were experimentally investigated.The decomposition characteristics of the hydrates under MW heating were analyzed based on the two-step dissociation mechanism accompanied by heat and mass transfer at the crystal surface.Results show that the decomposition behavior of the gas hydrate during MW heating is coupled with the real-time electromagnetic field.Volumetric heating enhances the heat and mass transfer process at the surface layer of the hydrate particles.The time-accumulated thermal effect of MW heating promotes the destruction of the clathrate host lattice.The average decomposition rates of ethane hydrate and propane hydrate obtained in this work range from 0.109 to 0.400 mol·min-1·L-1 and from 0.090 to 0.222 mol·min-1·L-1,respectively,under incident MW power that ranges from 120 to 540 W.We conclude that the average decomposition rates of ethane hydrate and propane hydrate are faster as the MW power increases within a certain range.The decomposition rates of ethane hydrate are mainly controlled by the MW power.In contrast,the decomposition rates of propane hydrate are controlled by both the MW power and the kinetic mechanism under relatively higher power.